Your mileage may vary... truly! You can go super cheap and gets prefolds/covers. Or you can do fitteds that have snaps with covers, All-in-ones (AIOs) that are multi-sized or more ambitiously "one sized" designed to last through potty training. You can use "pocket diapers" that you put inserts in.
I used:
Kissaluv Size 0 newborn with Bummi Super-whisper wraps (this would probably be a $100-200 investment, depending on new/used, how many, etc.) You can then resell these probably, they will go through the first few months and should be in good shape. Both my girls wore these, AND I lent them to a friend who had twins and THEN I sold them. (They were in very good condition, still). I liked them b/c you want a good fit with little babies (runny poop and all).
From 5/6 months through potty training, I used:
Fitted diapers (various brands, about 6-8) with Bummis or other covers (I used some wool covers too).
Fuzzy Bunz and other brand "pocket diapers" for nighttime- you can put extra stuffing in for nighttime.

(I had 3-5 of these, I think)
Bum Genius All-in-One diapers with velcro- maybe had about 6 of these? Had problems with the velcro, but would probably do snaps next time.
That was it. I bought most of my stash for my oldest (8 yo) and my second wore it (6 yo). I looked at them recently, they are still in good shape and don't smell weird or anything, so I could use many/most of them again.
I was impressed by Young House Love and their very minimal approach to cloth diapering... I had way more diapers than they had, but I'm intrigued by the simplicity of what they went with! I didn't think you could "get by" with only a dozen cloth diapers, so I was impressed.
http://www.younghouselove.com/2012/04/post-haste-2/
I'm sort of out of the loop on prices/where to buy, so can't help you with that. But much of what I used is still around today, I think... personally I would look at All-in-ones and pocket diapers, based on what me & dh liked...